drivers/net/wireless/intel/iwlwifi/dvm/scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called COPYING.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <linuxwifi@intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "dev.h"
  34 #include "agn.h"
  35
  36 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  37  * sending probe req.  This should be set long enough to hear probe responses
  38  * from more than one AP.  */
  39 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  40 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  41
  42 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  43 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  44
  45 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  46  * Must be set longer than active dwell time.
  47  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  48 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  49 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  50 #define IWL_PASSIVE_DWELL_BASE      (100)
  51 #define IWL_CHANNEL_TUNE_TIME       5
  52 #define MAX_SCAN_CHANNEL            50
  53
  54 /* For reset radio, need minimal dwell time only */
  55 #define IWL_RADIO_RESET_DWELL_TIME      5
  56
  57 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_host_cmd cmd = {
  61                 .id = REPLY_SCAN_ABORT_CMD,
  62                 .flags = CMD_WANT_SKB,
  63         };
  64         __le32 *status;
  65
  66         /* Exit instantly with error when device is not ready
  67          * to receive scan abort command or it does not perform
  68          * hardware scan currently */
  69         if (!test_bit(STATUS_READY, &priv->status) ||
  70             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  71             test_bit(STATUS_FW_ERROR, &priv->status))
  72                 return -EIO;
  73
  74         ret = iwl_dvm_send_cmd(priv, &cmd);
  75         if (ret)
  76                 return ret;
  77
  78         status = (void *)cmd.resp_pkt->data;
  79         if (*status != CAN_ABORT_STATUS) {
  80                 /* The scan abort will return 1 for success or
  81                  * 2 for "failure".  A failure condition can be
  82                  * due to simply not being in an active scan which
  83                  * can occur if we send the scan abort before we
  84                  * the microcode has notified us that a scan is
  85                  * completed. */
  86                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  87                                le32_to_cpu(*status));
  88                 ret = -EIO;
  89         }
  90
  91         iwl_free_resp(&cmd);
  92         return ret;
  93 }
  94
  95 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  96 {
  97         struct cfg80211_scan_info info = {
  98                 .aborted = aborted,
  99         };
 100
 101         /* check if scan was requested from mac80211 */
 102         if (priv->scan_request) {
 103                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 104                 ieee80211_scan_completed(priv->hw, &info);
 105         }
 106
 107         priv->scan_type = IWL_SCAN_NORMAL;
 108         priv->scan_vif = NULL;
 109         priv->scan_request = NULL;
 110 }
 111
 112 static void iwl_process_scan_complete(struct iwl_priv *priv)
 113 {
 114         bool aborted;
 115
 116         lockdep_assert_held(&priv->mutex);
 117
 118         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 119                 return;
 120
 121         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 122
 123         cancel_delayed_work(&priv->scan_check);
 124
 125         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 126         if (aborted)
 127                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 128
 129         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 130                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 131                 goto out_settings;
 132         }
 133
 134         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 135                 int err;
 136
 137                 /* Check if mac80211 requested scan during our internal scan */
 138                 if (priv->scan_request == NULL)
 139                         goto out_complete;
 140
 141                 /* If so request a new scan */
 142                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 143                                         priv->scan_request->channels[0]->band);
 144                 if (err) {
 145                         IWL_DEBUG_SCAN(priv,
 146                                 "failed to initiate pending scan: %d\n", err);
 147                         aborted = true;
 148                         goto out_complete;
 149                 }
 150
 151                 return;
 152         }
 153
 154 out_complete:
 155         iwl_complete_scan(priv, aborted);
 156
 157 out_settings:
 158         /* Can we still talk to firmware ? */
 159         if (!iwl_is_ready_rf(priv))
 160                 return;
 161
 162         iwlagn_post_scan(priv);
 163 }
 164
 165 void iwl_force_scan_end(struct iwl_priv *priv)
 166 {
 167         lockdep_assert_held(&priv->mutex);
 168
 169         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 170                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 171                 return;
 172         }
 173
 174         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 175         clear_bit(STATUS_SCANNING, &priv->status);
 176         clear_bit(STATUS_SCAN_HW, &priv->status);
 177         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 178         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 179         iwl_complete_scan(priv, true);
 180 }
 181
 182 static void iwl_do_scan_abort(struct iwl_priv *priv)
 183 {
 184         int ret;
 185
 186         lockdep_assert_held(&priv->mutex);
 187
 188         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 189                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 190                 return;
 191         }
 192
 193         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 194                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 195                 return;
 196         }
 197
 198         ret = iwl_send_scan_abort(priv);
 199         if (ret) {
 200                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 201                 iwl_force_scan_end(priv);
 202         } else
 203                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 204 }
 205
 206 /**
 207  * iwl_scan_cancel - Cancel any currently executing HW scan
 208  */
 209 int iwl_scan_cancel(struct iwl_priv *priv)
 210 {
 211         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 212         queue_work(priv->workqueue, &priv->abort_scan);
 213         return 0;
 214 }
 215
 216 /**
 217  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 218  * @ms: amount of time to wait (in milliseconds) for scan to abort
 219  *
 220  */
 221 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 222 {
 223         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 224
 225         lockdep_assert_held(&priv->mutex);
 226
 227         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 228
 229         iwl_do_scan_abort(priv);
 230
 231         while (time_before_eq(jiffies, timeout)) {
 232                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 233                         goto finished;
 234                 msleep(20);
 235         }
 236
 237         return;
 238
 239  finished:
 240         /*
 241          * Now STATUS_SCAN_HW is clear. This means that the
 242          * device finished, but the background work is going
 243          * to execute at best as soon as we release the mutex.
 244          * Since we need to be able to issue a new scan right
 245          * after this function returns, run the complete here.
 246          * The STATUS_SCAN_COMPLETE bit will then be cleared
 247          * and prevent the background work from "completing"
 248          * a possible new scan.
 249          */
 250         iwl_process_scan_complete(priv);
 251 }
 252
 253 /* Service response to REPLY_SCAN_CMD (0x80) */
 254 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 255                               struct iwl_rx_cmd_buffer *rxb)
 256 {
 257 #ifdef CONFIG_IWLWIFI_DEBUG
 258         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 259         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 260
 261         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 262 #endif
 263 }
 264
 265 /* Service SCAN_START_NOTIFICATION (0x82) */
 266 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 267                                     struct iwl_rx_cmd_buffer *rxb)
 268 {
 269         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 270         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 271
 272         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 273         IWL_DEBUG_SCAN(priv, "Scan start: "
 274                        "%d [802.11%s] "
 275                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 276                        notif->channel,
 277                        notif->band ? "bg" : "a",
 278                        le32_to_cpu(notif->tsf_high),
 279                        le32_to_cpu(notif->tsf_low),
 280                        notif->status, notif->beacon_timer);
 281 }
 282
 283 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 284 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 285                                       struct iwl_rx_cmd_buffer *rxb)
 286 {
 287 #ifdef CONFIG_IWLWIFI_DEBUG
 288         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 289         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 290
 291         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 292                        "%d [802.11%s] "
 293                        "probe status: %u:%u "
 294                        "(TSF: 0x%08X:%08X) - %d "
 295                        "elapsed=%lu usec\n",
 296                        notif->channel,
 297                        notif->band ? "bg" : "a",
 298                        notif->probe_status, notif->num_probe_not_sent,
 299                        le32_to_cpu(notif->tsf_high),
 300                        le32_to_cpu(notif->tsf_low),
 301                        le32_to_cpu(notif->statistics[0]),
 302                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 303 #endif
 304 }
 305
 306 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 307 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 308                                        struct iwl_rx_cmd_buffer *rxb)
 309 {
 310         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 311         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 312
 313         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 314                        scan_notif->scanned_channels,
 315                        scan_notif->tsf_low,
 316                        scan_notif->tsf_high, scan_notif->status);
 317
 318         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 319                        (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
 320                        jiffies_to_msecs(jiffies - priv->scan_start));
 321
 322         /*
 323          * When aborting, we run the scan completed background work inline
 324          * and the background work must then do nothing. The SCAN_COMPLETE
 325          * bit helps implement that logic and thus needs to be set before
 326          * queueing the work. Also, since the scan abort waits for SCAN_HW
 327          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 328          * to avoid a race there.
 329          */
 330         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 331         clear_bit(STATUS_SCAN_HW, &priv->status);
 332         queue_work(priv->workqueue, &priv->scan_completed);
 333
 334         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 335             iwl_advanced_bt_coexist(priv) &&
 336             priv->bt_status != scan_notif->bt_status) {
 337                 if (scan_notif->bt_status) {
 338                         /* BT on */
 339                         if (!priv->bt_ch_announce)
 340                                 priv->bt_traffic_load =
 341                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 342                         /*
 343                          * otherwise, no traffic load information provided
 344                          * no changes made
 345                          */
 346                 } else {
 347                         /* BT off */
 348                         priv->bt_traffic_load =
 349                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 350                 }
 351                 priv->bt_status = scan_notif->bt_status;
 352                 queue_work(priv->workqueue,
 353                            &priv->bt_traffic_change_work);
 354         }
 355 }
 356
 357 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 358 {
 359         /* scan handlers */
 360         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 361         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 362         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 363                                         iwl_rx_scan_results_notif;
 364         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 365                                         iwl_rx_scan_complete_notif;
 366 }
 367
 368 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 369                                      enum nl80211_band band, u8 n_probes)
 370 {
 371         if (band == NL80211_BAND_5GHZ)
 372                 return IWL_ACTIVE_DWELL_TIME_52 +
 373                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 374         else
 375                 return IWL_ACTIVE_DWELL_TIME_24 +
 376                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 377 }
 378
 379 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 380 {
 381         struct iwl_rxon_context *ctx;
 382         int limits[NUM_IWL_RXON_CTX] = {};
 383         int n_active = 0;
 384         u16 limit;
 385
 386         BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 387
 388         /*
 389          * If we're associated, we clamp the dwell time 98%
 390          * of the beacon interval (minus 2 * channel tune time)
 391          * If both contexts are active, we have to restrict to
 392          * 1/2 of the minimum of them, because they might be in
 393          * lock-step with the time inbetween only half of what
 394          * time we'd have in each of them.
 395          */
 396         for_each_context(priv, ctx) {
 397                 switch (ctx->staging.dev_type) {
 398                 case RXON_DEV_TYPE_P2P:
 399                         /* no timing constraints */
 400                         continue;
 401                 case RXON_DEV_TYPE_ESS:
 402                 default:
 403                         /* timing constraints if associated */
 404                         if (!iwl_is_associated_ctx(ctx))
 405                                 continue;
 406                         break;
 407                 case RXON_DEV_TYPE_CP:
 408                 case RXON_DEV_TYPE_2STA:
 409                         /*
 410                          * These seem to always have timers for TBTT
 411                          * active in uCode even when not associated yet.
 412                          */
 413                         break;
 414                 }
 415
 416                 limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 417         }
 418
 419         switch (n_active) {
 420         case 0:
 421                 return dwell_time;
 422         case 2:
 423                 limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 424                 limit /= 2;
 425                 dwell_time = min(limit, dwell_time);
 426                 /* fall through to limit further */
 427         case 1:
 428                 limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 429                 limit /= n_active;
 430                 return min(limit, dwell_time);
 431         default:
 432                 WARN_ON_ONCE(1);
 433                 return dwell_time;
 434         }
 435 }
 436
 437 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 438                                       enum nl80211_band band)
 439 {
 440         u16 passive = (band == NL80211_BAND_2GHZ) ?
 441             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 442             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 443
 444         return iwl_limit_dwell(priv, passive);
 445 }
 446
 447 /* Return valid, unused, channel for a passive scan to reset the RF */
 448 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 449                                         enum nl80211_band band)
 450 {
 451         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 452         struct iwl_rxon_context *ctx;
 453         int i;
 454
 455         for (i = 0; i < sband->n_channels; i++) {
 456                 bool busy = false;
 457
 458                 for_each_context(priv, ctx) {
 459                         busy = sband->channels[i].hw_value ==
 460                                 le16_to_cpu(ctx->staging.channel);
 461                         if (busy)
 462                                 break;
 463                 }
 464
 465                 if (busy)
 466                         continue;
 467
 468                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 469                         return sband->channels[i].hw_value;
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 476                                           struct ieee80211_vif *vif,
 477                                           enum nl80211_band band,
 478                                           struct iwl_scan_channel *scan_ch)
 479 {
 480         const struct ieee80211_supported_band *sband;
 481         u16 channel;
 482
 483         sband = iwl_get_hw_mode(priv, band);
 484         if (!sband) {
 485                 IWL_ERR(priv, "invalid band\n");
 486                 return 0;
 487         }
 488
 489         channel = iwl_get_single_channel_number(priv, band);
 490         if (channel) {
 491                 scan_ch->channel = cpu_to_le16(channel);
 492                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 493                 scan_ch->active_dwell =
 494                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 495                 scan_ch->passive_dwell =
 496                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 497                 /* Set txpower levels to defaults */
 498                 scan_ch->dsp_atten = 110;
 499                 if (band == NL80211_BAND_5GHZ)
 500                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 501                 else
 502                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 503                 return 1;
 504         }
 505
 506         IWL_ERR(priv, "no valid channel found\n");
 507         return 0;
 508 }
 509
 510 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 511                                      struct ieee80211_vif *vif,
 512                                      enum nl80211_band band,
 513                                      u8 is_active, u8 n_probes,
 514                                      struct iwl_scan_channel *scan_ch)
 515 {
 516         struct ieee80211_channel *chan;
 517         const struct ieee80211_supported_band *sband;
 518         u16 passive_dwell = 0;
 519         u16 active_dwell = 0;
 520         int added, i;
 521         u16 channel;
 522
 523         sband = iwl_get_hw_mode(priv, band);
 524         if (!sband)
 525                 return 0;
 526
 527         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 528         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 529
 530         if (passive_dwell <= active_dwell)
 531                 passive_dwell = active_dwell + 1;
 532
 533         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 534                 chan = priv->scan_request->channels[i];
 535
 536                 if (chan->band != band)
 537                         continue;
 538
 539                 channel = chan->hw_value;
 540                 scan_ch->channel = cpu_to_le16(channel);
 541
 542                 if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 543                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 544                 else
 545                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 546
 547                 if (n_probes)
 548                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 549
 550                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 551                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 552
 553                 /* Set txpower levels to defaults */
 554                 scan_ch->dsp_atten = 110;
 555
 556                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 557                  * power level:
 558                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 559                  */
 560                 if (band == NL80211_BAND_5GHZ)
 561                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 562                 else
 563                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 564
 565                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 566                                channel, le32_to_cpu(scan_ch->type),
 567                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 568                                 "ACTIVE" : "PASSIVE",
 569                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 570                                active_dwell : passive_dwell);
 571
 572                 scan_ch++;
 573                 added++;
 574         }
 575
 576         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 577         return added;
 578 }
 579
 580 /**
 581  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 582  */
 583
 584 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 585                               const u8 *ies, int ie_len, const u8 *ssid,
 586                               u8 ssid_len, int left)
 587 {
 588         int len = 0;
 589         u8 *pos = NULL;
 590
 591         /* Make sure there is enough space for the probe request,
 592          * two mandatory IEs and the data */
 593         left -= 24;
 594         if (left < 0)
 595                 return 0;
 596
 597         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 598         eth_broadcast_addr(frame->da);
 599         memcpy(frame->sa, ta, ETH_ALEN);
 600         eth_broadcast_addr(frame->bssid);
 601         frame->seq_ctrl = 0;
 602
 603         len += 24;
 604
 605         /* ...next IE... */
 606         pos = &frame->u.probe_req.variable[0];
 607
 608         /* fill in our SSID IE */
 609         left -= ssid_len + 2;
 610         if (left < 0)
 611                 return 0;
 612         *pos++ = WLAN_EID_SSID;
 613         *pos++ = ssid_len;
 614         if (ssid && ssid_len) {
 615                 memcpy(pos, ssid, ssid_len);
 616                 pos += ssid_len;
 617         }
 618
 619         len += ssid_len + 2;
 620
 621         if (WARN_ON(left < ie_len))
 622                 return len;
 623
 624         if (ies && ie_len) {
 625                 memcpy(pos, ies, ie_len);
 626                 len += ie_len;
 627         }
 628
 629         return (u16)len;
 630 }
 631
 632 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 633 {
 634         struct iwl_host_cmd cmd = {
 635                 .id = REPLY_SCAN_CMD,
 636                 .len = { sizeof(struct iwl_scan_cmd), },
 637         };
 638         struct iwl_scan_cmd *scan;
 639         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 640         u32 rate_flags = 0;
 641         u16 cmd_len = 0;
 642         u16 rx_chain = 0;
 643         enum nl80211_band band;
 644         u8 n_probes = 0;
 645         u8 rx_ant = priv->nvm_data->valid_rx_ant;
 646         u8 rate;
 647         bool is_active = false;
 648         int  chan_mod;
 649         u8 active_chains;
 650         u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 651         int ret;
 652         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 653                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 654                             priv->fw->ucode_capa.max_probe_length;
 655         const u8 *ssid = NULL;
 656         u8 ssid_len = 0;
 657
 658         if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 659                     (!priv->scan_request ||
 660                      priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 661                 return -EINVAL;
 662
 663         lockdep_assert_held(&priv->mutex);
 664
 665         if (vif)
 666                 ctx = iwl_rxon_ctx_from_vif(vif);
 667
 668         if (!priv->scan_cmd) {
 669                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 670                 if (!priv->scan_cmd) {
 671                         IWL_DEBUG_SCAN(priv,
 672                                        "fail to allocate memory for scan\n");
 673                         return -ENOMEM;
 674                 }
 675         }
 676         scan = priv->scan_cmd;
 677         memset(scan, 0, scan_cmd_size);
 678
 679         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 680         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 681
 682         if (iwl_is_any_associated(priv)) {
 683                 u16 interval = 0;
 684                 u32 extra;
 685                 u32 suspend_time = 100;
 686                 u32 scan_suspend_time = 100;
 687
 688                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 689                 switch (priv->scan_type) {
 690                 case IWL_SCAN_RADIO_RESET:
 691                         interval = 0;
 692                         break;
 693                 case IWL_SCAN_NORMAL:
 694                         interval = vif->bss_conf.beacon_int;
 695                         break;
 696                 }
 697
 698                 scan->suspend_time = 0;
 699                 scan->max_out_time = cpu_to_le32(200 * 1024);
 700                 if (!interval)
 701                         interval = suspend_time;
 702
 703                 extra = (suspend_time / interval) << 22;
 704                 scan_suspend_time = (extra |
 705                     ((suspend_time % interval) * 1024));
 706                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 707                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 708                                scan_suspend_time, interval);
 709         }
 710
 711         switch (priv->scan_type) {
 712         case IWL_SCAN_RADIO_RESET:
 713                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 714                 /*
 715                  * Override quiet time as firmware checks that active
 716                  * dwell is >= quiet; since we use passive scan it'll
 717                  * not actually be used.
 718                  */
 719                 scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 720                 break;
 721         case IWL_SCAN_NORMAL:
 722                 if (priv->scan_request->n_ssids) {
 723                         int i, p = 0;
 724                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 725                         /*
 726                          * The highest priority SSID is inserted to the
 727                          * probe request template.
 728                          */
 729                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 730                         ssid = priv->scan_request->ssids[0].ssid;
 731
 732                         /*
 733                          * Invert the order of ssids, the firmware will invert
 734                          * it back.
 735                          */
 736                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 737                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 738                                 scan->direct_scan[p].len =
 739                                         priv->scan_request->ssids[i].ssid_len;
 740                                 memcpy(scan->direct_scan[p].ssid,
 741                                        priv->scan_request->ssids[i].ssid,
 742                                        priv->scan_request->ssids[i].ssid_len);
 743                                 n_probes++;
 744                                 p++;
 745                         }
 746                         is_active = true;
 747                 } else
 748                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 749                 break;
 750         }
 751
 752         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 753         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 754         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 755
 756         switch (priv->scan_band) {
 757         case NL80211_BAND_2GHZ:
 758                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 759                 chan_mod = le32_to_cpu(
 760                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 761                                                 RXON_FLG_CHANNEL_MODE_MSK)
 762                                        >> RXON_FLG_CHANNEL_MODE_POS;
 763                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 764                     chan_mod == CHANNEL_MODE_PURE_40) {
 765                         rate = IWL_RATE_6M_PLCP;
 766                 } else {
 767                         rate = IWL_RATE_1M_PLCP;
 768                         rate_flags = RATE_MCS_CCK_MSK;
 769                 }
 770                 /*
 771                  * Internal scans are passive, so we can indiscriminately set
 772                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 773                  */
 774                 if (priv->lib->bt_params &&
 775                     priv->lib->bt_params->advanced_bt_coexist)
 776                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 777                 break;
 778         case NL80211_BAND_5GHZ:
 779                 rate = IWL_RATE_6M_PLCP;
 780                 break;
 781         default:
 782                 IWL_WARN(priv, "Invalid scan band\n");
 783                 return -EIO;
 784         }
 785
 786         /*
 787          * If active scanning is requested but a certain channel is
 788          * marked passive, we can do active scanning if we detect
 789          * transmissions.
 790          *
 791          * There is an issue with some firmware versions that triggers
 792          * a sysassert on a "good CRC threshold" of zero (== disabled),
 793          * on a radar channel even though this means that we should NOT
 794          * send probes.
 795          *
 796          * The "good CRC threshold" is the number of frames that we
 797          * need to receive during our dwell time on a channel before
 798          * sending out probes -- setting this to a huge value will
 799          * mean we never reach it, but at the same time work around
 800          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 801          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 802          *
 803          * This was fixed in later versions along with some other
 804          * scan changes, and the threshold behaves as a flag in those
 805          * versions.
 806          */
 807         if (priv->new_scan_threshold_behaviour)
 808                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 809                                                 IWL_GOOD_CRC_TH_DISABLED;
 810         else
 811                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 812                                                 IWL_GOOD_CRC_TH_NEVER;
 813
 814         band = priv->scan_band;
 815
 816         if (band == NL80211_BAND_2GHZ &&
 817             priv->lib->bt_params &&
 818             priv->lib->bt_params->advanced_bt_coexist) {
 819                 /* transmit 2.4 GHz probes only on first antenna */
 820                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 821         }
 822
 823         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 824                                                     priv->scan_tx_ant[band],
 825                                                     scan_tx_antennas);
 826         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 827         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 828
 829         /*
 830          * In power save mode while associated use one chain,
 831          * otherwise use all chains
 832          */
 833         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 834             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 835                 /* rx_ant has been set to all valid chains previously */
 836                 active_chains = rx_ant &
 837                                 ((u8)(priv->chain_noise_data.active_chains));
 838                 if (!active_chains)
 839                         active_chains = rx_ant;
 840
 841                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 842                                 priv->chain_noise_data.active_chains);
 843
 844                 rx_ant = first_antenna(active_chains);
 845         }
 846         if (priv->lib->bt_params &&
 847             priv->lib->bt_params->advanced_bt_coexist &&
 848             priv->bt_full_concurrent) {
 849                 /* operated as 1x1 in full concurrency mode */
 850                 rx_ant = first_antenna(rx_ant);
 851         }
 852
 853         /* MIMO is not used here, but value is required */
 854         rx_chain |=
 855                 priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 856         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 857         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 858         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 859         scan->rx_chain = cpu_to_le16(rx_chain);
 860         switch (priv->scan_type) {
 861         case IWL_SCAN_NORMAL:
 862                 cmd_len = iwl_fill_probe_req(
 863                                         (struct ieee80211_mgmt *)scan->data,
 864                                         vif->addr,
 865                                         priv->scan_request->ie,
 866                                         priv->scan_request->ie_len,
 867                                         ssid, ssid_len,
 868                                         scan_cmd_size - sizeof(*scan));
 869                 break;
 870         case IWL_SCAN_RADIO_RESET:
 871                 /* use bcast addr, will not be transmitted but must be valid */
 872                 cmd_len = iwl_fill_probe_req(
 873                                         (struct ieee80211_mgmt *)scan->data,
 874                                         iwl_bcast_addr, NULL, 0,
 875                                         NULL, 0,
 876                                         scan_cmd_size - sizeof(*scan));
 877                 break;
 878         default:
 879                 BUG();
 880         }
 881         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 882
 883         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 884                                RXON_FILTER_BCON_AWARE_MSK);
 885
 886         switch (priv->scan_type) {
 887         case IWL_SCAN_RADIO_RESET:
 888                 scan->channel_count =
 889                         iwl_get_channel_for_reset_scan(priv, vif, band,
 890                                 (void *)&scan->data[cmd_len]);
 891                 break;
 892         case IWL_SCAN_NORMAL:
 893                 scan->channel_count =
 894                         iwl_get_channels_for_scan(priv, vif, band,
 895                                 is_active, n_probes,
 896                                 (void *)&scan->data[cmd_len]);
 897                 break;
 898         }
 899
 900         if (scan->channel_count == 0) {
 901                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 902                 return -EIO;
 903         }
 904
 905         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 906             scan->channel_count * sizeof(struct iwl_scan_channel);
 907         cmd.data[0] = scan;
 908         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 909         scan->len = cpu_to_le16(cmd.len[0]);
 910
 911         /* set scan bit here for PAN params */
 912         set_bit(STATUS_SCAN_HW, &priv->status);
 913
 914         ret = iwlagn_set_pan_params(priv);
 915         if (ret) {
 916                 clear_bit(STATUS_SCAN_HW, &priv->status);
 917                 return ret;
 918         }
 919
 920         ret = iwl_dvm_send_cmd(priv, &cmd);
 921         if (ret) {
 922                 clear_bit(STATUS_SCAN_HW, &priv->status);
 923                 iwlagn_set_pan_params(priv);
 924         }
 925
 926         return ret;
 927 }
 928
 929 void iwl_init_scan_params(struct iwl_priv *priv)
 930 {
 931         u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
 932         if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
 933                 priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
 934         if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
 935                 priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
 936 }
 937
 938 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 939                                    struct ieee80211_vif *vif,
 940                                    enum iwl_scan_type scan_type,
 941                                    enum nl80211_band band)
 942 {
 943         int ret;
 944
 945         lockdep_assert_held(&priv->mutex);
 946
 947         cancel_delayed_work(&priv->scan_check);
 948
 949         if (!iwl_is_ready_rf(priv)) {
 950                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 951                 return -EIO;
 952         }
 953
 954         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 955                 IWL_DEBUG_SCAN(priv,
 956                         "Multiple concurrent scan requests in parallel.\n");
 957                 return -EBUSY;
 958         }
 959
 960         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 961                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 962                 return -EBUSY;
 963         }
 964
 965         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 966                         scan_type == IWL_SCAN_NORMAL ? "" :
 967                         "internal short ");
 968
 969         set_bit(STATUS_SCANNING, &priv->status);
 970         priv->scan_type = scan_type;
 971         priv->scan_start = jiffies;
 972         priv->scan_band = band;
 973
 974         ret = iwlagn_request_scan(priv, vif);
 975         if (ret) {
 976                 clear_bit(STATUS_SCANNING, &priv->status);
 977                 priv->scan_type = IWL_SCAN_NORMAL;
 978                 return ret;
 979         }
 980
 981         queue_delayed_work(priv->workqueue, &priv->scan_check,
 982                            IWL_SCAN_CHECK_WATCHDOG);
 983
 984         return 0;
 985 }
 986
 987
 988 /*
 989  * internal short scan, this function should only been called while associated.
 990  * It will reset and tune the radio to prevent possible RF related problem
 991  */
 992 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 993 {
 994         queue_work(priv->workqueue, &priv->start_internal_scan);
 995 }
 996
 997 static void iwl_bg_start_internal_scan(struct work_struct *work)
 998 {
 999         struct iwl_priv *priv =
1000                 container_of(work, struct iwl_priv, start_internal_scan);
1001
1002         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1003
1004         mutex_lock(&priv->mutex);
1005
1006         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1007                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1008                 goto unlock;
1009         }
1010
1011         if (test_bit(STATUS_SCANNING, &priv->status)) {
1012                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1013                 goto unlock;
1014         }
1015
1016         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1017                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1018  unlock:
1019         mutex_unlock(&priv->mutex);
1020 }
1021
1022 static void iwl_bg_scan_check(struct work_struct *data)
1023 {
1024         struct iwl_priv *priv =
1025             container_of(data, struct iwl_priv, scan_check.work);
1026
1027         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1028
1029         /* Since we are here firmware does not finish scan and
1030          * most likely is in bad shape, so we don't bother to
1031          * send abort command, just force scan complete to mac80211 */
1032         mutex_lock(&priv->mutex);
1033         iwl_force_scan_end(priv);
1034         mutex_unlock(&priv->mutex);
1035 }
1036
1037 static void iwl_bg_abort_scan(struct work_struct *work)
1038 {
1039         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1040
1041         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1042
1043         /* We keep scan_check work queued in case when firmware will not
1044          * report back scan completed notification */
1045         mutex_lock(&priv->mutex);
1046         iwl_scan_cancel_timeout(priv, 200);
1047         mutex_unlock(&priv->mutex);
1048 }
1049
1050 static void iwl_bg_scan_completed(struct work_struct *work)
1051 {
1052         struct iwl_priv *priv =
1053                 container_of(work, struct iwl_priv, scan_completed);
1054
1055         mutex_lock(&priv->mutex);
1056         iwl_process_scan_complete(priv);
1057         mutex_unlock(&priv->mutex);
1058 }
1059
1060 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1061 {
1062         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1063         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1064         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1065         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1066 }
1067
1068 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1069 {
1070         cancel_work_sync(&priv->start_internal_scan);
1071         cancel_work_sync(&priv->abort_scan);
1072         cancel_work_sync(&priv->scan_completed);
1073
1074         if (cancel_delayed_work_sync(&priv->scan_check)) {
1075                 mutex_lock(&priv->mutex);
1076                 iwl_force_scan_end(priv);
1077                 mutex_unlock(&priv->mutex);
1078         }
1079 }